When one or both of a patient's alveolar ridges (e.g., the two jaw ridges, one jaw ridge being generally located on the roof of the mouth between the upper teeth and the hard palate while the other jaw ridge is generally located on the bottom of the mouth behind the lower teeth) are rendered edentulous (i.e., toothless), full plate dentures may be desirable to restore the patient's bite. However, generating a denture or denture set for a partially or completely edentulous patient often involves numerous steps, requiring the patient to make multiple visits to their dental care provider. A first patient visit can include generating a preliminary impression mold by applying a stock dental impression tray filled with an impression material (e.g., alginate) to one or more of the patient's alveolar ridges, allowing the impression material to cure, and removing the cured impression material from the patient's mouth thereby forming the preliminary impression mold. A preliminary impression mold may be used to generate one or more custom dental impression trays. At a second patient visit, the custom dental impression trays may be filled with impression material (e.g., PVS or polyether) and applied to the patient's alveolar ridges to make one or more master impressions. Upon the substantial curing of the impression material, the trays with their alveolar ridges master impressions (e.g., an impression cavity) can be removed from the patient's mouth and used to make a record base and wax rim combination and a master cast. Master casts (e.g., models) of the alveolar ridge(s) may be manufactured by filling in the impression cavity and surrounding area with casting material (e.g., dental stone). Once the casting material has cured, the master cast can be removed from the master impression.
At a third patient visit, the combination could be applied to the alveolar ridges, the record base can be used to check the patient's existing edentulous bite while the wax rims can be contoured for lip support, future incisal edge position, occlusal plane, occlusal vertical dimension and midline. The patient's facebow transfer and bite registration can be recorded at this time for the correct vertical dimension. The artificial teeth may be also selected for tooth model, tooth shade and desired occlusal scheme.
The recorded information, artificial teeth selection, and master casts may then be used to create an initial or temporary denture set. The master casts can be set in an articulator, a hinged device that holds the castings in opposing positions to generally allow the castings to replicate the patient's jaw hinge movement and bite relationship. The combination or a bite block can also be placed between the two castings to show the patient's current bite alignment of the two jaws. That bite block information could then be used formulate or otherwise identify what the proper alignment of the two jaws would be when the teeth (artificial) are located upon the alveolar ridge(s). Bite block information, aesthetics, and other oral considerations can be used to help identify how and where the artificial teeth can be applied to the casts by warmed dental wax. The teeth-to-cast application may be a complete set-up of all the artificial teeth, or a partial set-up with only the maxillary anterior teeth (e.g., front bottom and top teeth). In the event that a partial set-up is used, additional patient appointments may be used to set the remaining teeth. The sequence of artificial teeth application could start with the top front teeth being attached and aligned, followed by the bottom front teeth, then sets of side teeth, and lastly the molars. The articulator can be opened and closed during the artificial teeth application process to substantially evaluate how the bite reconstruction is progressing. Once the artificial teeth are set in place, teeth-cast combinations can be removed from the articulator to facilitate the building up of the gum portion of upon the master casts using additional dental wax to finally form the temporary or intermediate wax gum-artificial teeth denture.
At yet another patient visit, temporary or intermediate (e.g., wax gum-artificial teeth) dentures can be removed from the master casts and evaluated on the patient for accuracy of mounting, occlusal vertical dimension, esthetics, and phonetics. Appropriate adjustment to the dentures can be made as needed (e.g., wax gum underside could be adjusted to improve the wax gum-to-alveolar ridge fit).
In some cases, for example where a denture was not fitted to the patient (e.g., remained attached to the casting) or where a temporary denture was fitted and adjusted, a next step may include replacing a wax gum with an acrylic gum. This may involve placing a protective polymer coating (e.g., Blu Mousse®) on the set of artificial teeth. The casting and wax denture combination can then be sprayed with a releasing agent and placed into a dental flask (e.g., a mold-forming two part container) that is partially filled with dental stone. After the bottom of the casting is placed within the dental flask and generally applied to the dental stone, a wax vent sprue may be attached to the exposed wax gum. Additional dental stone can be applied though an opening in the assembled flask to cover up the remaining uncovered portion of the casting and the wax vent sprue. After the dental stone has dried, the flask could be heated in hot water bath to allow the wax gum and sprue to melt and then be poured out of the flask to form hollow gum cavity. An open-ended cylinder containing dental acrylic can then be applied to the flask to inject the dental acrylic into the hollow gum cavity formed by the removal/melting of the wax vent sprue. The flask-cylinder combination can be placed into an injection machine that could use mechanical, hydraulic, or pneumatic pressure means to inject the acrylic from the cylinder into the hollow gum cavity. The injected dental acrylic could then be fixed or cured (e.g., by heat when the entire flask is placed in a hot water bath). After curing of the acrylic gum, the flask can be opened to release the stone-encased formed denture. After carefully removing the stone covering and casting away from the denture, the protective polymer can be exposed and removed from the teeth. The denture can then be cleaned up and an additional appointment made with the patient for denture application, final fitting, and adjustment. Additional patient appointments may be made for further denture fitting observations and adjustments.
As can be appreciated the above denture manufacture procedure may require significant time, money, materials and numerous patient visits before producing a usable denture(s). The following disclosure describes, in some embodiments, a dental impression tray system configured to significantly bypass, incorporate, or eliminate several of the denture making steps and may reduce the time, costs, materials, and number of patient visits needed to produce a denture.